The burly nightclub bouncer who raped and strangled John Jay College grad student Imette St. Guillen was convicted yesterday of first-degree murder — assuring the ex-con will spend the rest of his days behind bars.

Darryl Littlejohn, 44, was found guilty after prosecutors proved he befriended St. Guillen at The Falls — the SoHo bar where he worked as a bouncer — in February 2006, lured her into his van, drove her to Brooklyn and killed her.

Littlejohn sat stone-faced as the verdict was read aloud in Brooklyn Supreme Court, while St. Guillen’s mother and sister — holding each other in the back of the packed room — wept with emotion.

“Imette was a caring young woman, an amazing daughter, sister and friend,” St. Guillen’s mother, Maureen, said outside the courthouse.

“Her love and caring for others was never-ending.”

Throughout the monthlong trial, defense lawyer Joyce David had tried to convince the jury that Littlejohn was the victim of a massive conspiracy to shield well-connected Falls bar manager Danny Dorrian, claiming that Dorrian accidentally killed St. Guillen, 24, after a night of sexual-domination play.

David also tried to play up the fact that the barkeep’s family ran Dorrian’s Red Hand, the infamous Upper East Side bar where “Preppy Killer” Robert Chambers met his victim, Jennifer Levin, in 1986 before strangling her during rough sex in Central Park.

But jurors didn’t fall for the argument — taking only seven hours to reach a verdict.

Prosecutors presented a raft of damning evidence against Littlejohn — including testimony from DNA experts who said a tiny drop of his blood was found on a plastic tie used to bind the Boston native’s wrists.

Cellphone-tower records also put him near where her body was found the night of the murder.

“There were so many things that kept adding up,” said one juror, who asked that her name not be printed.

“The blood on the [wrist] ties, the cellphone towers, asking his girlfriend to give him an alibi. It all kept adding up and, in the end, nobody had any doubts. It was an easy decision.”

Littlejohn faces life in prison without the possibility of parole when he is sentenced July 8.

He is already serving a 25-years-to-life sentence for kidnapping a college student in Queens in 2005 — a crime police said was part of a sex-attack spree.

“The defense did everything they could to discredit the case, and I thank you for your ability to come to your decision so we can at last get justice,” Maureen St. Guillen said, referring to the jurors.

But David maintained her client’s innocence: “I hope the family gets some closure from this, but I believe they have the wrong man,” she said.

St. Guillen’s naked body was discovered on a desolate stretch of road in East New York on February 25, 2006, a day after she was last seen hanging out with friends in SoHo.

She was wrapped in a dirty bedspread, bound and gagged, and had been sexually assaulted.